IC-NRLF 


THE  TECHNIQUE  OF 
ARMY  TRAINING 


WAR  DEPARTMENT 

ADJUTANT  GEM  —     >         >I  FICE 


1922 


C\J 

-co 

CO 
CM 


O 


WASHINGTON 

GOVERN  VM.V« 

1922 


GIFT   OF 


THE  TECHNIQUE  OF 
ARMY  TRAINING 


WAR  DEPARTMENT 

THE  ADJUTANT  GENERAL'S  OFFICE 


1922 


WASHINGTON 
GOVERNMENT  PRINTING  OFFICE 

1922 


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OF  THIS  PUBLICATION  MAY  BE  PROCURED  FROM 

THE  SUPERINTENDENT  OF  DOCUMENTS 

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5 


V 


THE  TECHNIQUE  OF  ARMY  TRAINING. 


INTRODUCTION. 

In  a  major  emergency,  speed  of  organization  and  of  training  troops 
is  of  primary  importance.  Rapid  and  thorough  training  methods 
are  also  essential  to  success  with  the  National  Guard,  the  Organized 
Reserves,  and  the  citizens  military  training  camps  in  time  of  peace. 
Nothing  so  stimulates  interest  in  these  organizations  and  makes  men 
enthusiastic  in  their  support  as  a  snappy,  progressive  schedule  that 
leaves  every  man  with  a  sense  of  satisfaction  at  his  personal  progress 
for  each  day's  work. 

For  these  reasons  the  development  of  army  training  methods,  until 
they  achieve  the  results  required  with  maximum  thoroughness  in  mini- 
mum time,  will  be  given  great  weight  in  the  Military  Establishment. 
This  document  on  technique  of  army  training  summarizes  the  best 
practice  in  this  matter  as  developed  by  war  experience  and  since. 
Sections  I  to  VII  define  the  essential  elements  of  a  sound  training 
program  and  the  procedure  for  producing  the  necessary  aids  to  in- 
struction. Section  VIII  presents  the  solution  of  the  problem  for  a 
single  type  of  technical  specialist,  the  radio  operator.  This  typical 
illustration  outlines  the  several  steps  that  must  be  taken  and  the  docu- 
ments that  must  be  prepared  for  every  phase  of  army  training  before 
firm  foundations  for  a  well  coordinated  and  efficient  system  will  be 
laid. 

Documents  do  not  produce  training.  They  define  objectives  and 
assign  missions.  Educational  experience  has  demonstrated  unequivo- 
cally that  the  more  clearly  the  objective  is  defined  and  the  more 
specifically  the  mission  is  described,  the  greater  the  success  of  in- 
struction. The  best  marksman  can  not  hit  the  bull's-eye  unless  he 
sees  the  target.  The  best  instructors  likewise  must  have  their  ob- 
jectives and  missions  well  defined  by  specifications,  standards,  and 
job  analyses,  as  herein  described,  before  they  can  achieve  maximum 
thoroughness  of  instruction  in  minimum  time. 

I.  PERSONNEL  SPECIFICATIONS. — In  order  that  the  man  power  of  the 
Army  may  be  utilized  to  its  maximum  efficiency,  not  only  in  time  of 
peace  but  more  especially  in  time  of  war,  it  is  essential  that  each  man 

3 

487353 


4  TICK   TECHNIQUE   OF   ARMY  TRAINING. 

be  assigned  to  duty  where  his  services  will  count  most.  The  first  step 
in  achieving  this  objective  is  the  preparation  of  personnel  specifica- 
tions which  define  briefly  the  personal  characteristics,  skill,  and 
knowledge  needed  to  perform  efficiently  every  type  of  service  re- 
quired in  the  Army. 

The  first  important  function  of  personnel  specifications  is  that  of 
an  index  or  catalogue  by  which  a  unit  commander  can  requisition 
men  needed  to  complete  his  organization.  They  are  used  in  this  way 
when  there  is  available  a  large  number  of  men  of  all  kinds  and  the 
problem  is  to  assign  each  man  quickly  where  his  specific  abilities  will 
enable  him  to  render  the  greatest  service.  They  furnish  the  standard 
terminology  by  means  of  which  personnel  officers  classify  available 
men  in  the  same  categories  used  by  commanding  officers  in  requisi- 
tioning men. 

Personnel  specifications  have  a  second  important  function.  They 
define  the  objective  which  training  for  every  type  of  service  must 
achieve.  They  are  the  guide  in  constructing  courses  of  instruction  to 
train  raw  or  partly  qualified  men  to  meet  the  requirements.  The  per- 
sonal characteristics  indicate  the  tj^pe  of  men  to  select  for  each  type 
of  training,  and  the  skill  and  knowledge  specifications  define  what  the 
man  must  be  made  to  master  by  the  instruction. 

II.  MINIMUM  SPECIFICATIONS. — It  is  of  the  utmost  importance  that 
the  assignment  of  men  to  military  organizations  be  so  made  that 
the  combat  branches,  on  which  success  in  battle  primarily  depends, 
secure  the  requisite  amount  of  intelligence  and  leadership.  There- 
fore, specifications  for  personnel  of  the  noncombatant  branches  and 
for  technical  specialists  of  the  combatant  branches  should  mention 
only  the  indispensable  personal  characteristics  and  the  lowest  ac- 
ceptable standards  of  skill  and  knowledge  essential  for  proficiency 
in  each  grade  or  rating.  If  these  specifications  really  contain  only 
the  minimum  requirements,  and  if  all  officers  concerned  adhere  to 
them  accurately,  they  are  a  powerful  and  essential  tool  in  conserving 
man  power.  Such  specifications  are  called  minimum  specifications 
to  distinguish  them  from  specifications  that  call  for  degrees  of  skill 
and  knowledge  higher  than  those  actually  needed  to  do  the  job. 

Since  personnel  specifications  also  define  the  objectives  of  training, 
they  should  mention  only  the  essential  requirements  for  proficiency 
in  order  to  make  possible  maximum  thoroughness  of  training  in 
minimum  time. 

Minimum  specifications  are  statements  of  the  essential  specific 
abilities  and  the  lowest  acceptable  standards  for  a  given  grade  or 
rating. 

Specific  abilities  mentioned  in  minimum  specifications  are  of  three 
kinds,  namely : 


INTRODUCTION.  5 

(a)  Skill:  A  list  of  the  things  a  man  must  be  able  to  do  well  in 
order  to  qualify  for  the  grade  or  rating. 

(b)  Knowledge:  A  list  of  the  things  a  man  must  know  in  order 
to  qualify  for  the  grade  or  rating. 

(c)  Personal  characteristics:  Those  characteristics  of  physique, 
temperament,  and  natural  bent  essential  for  the  required  degree  of 
proficiency. 

/Standards  mentioned  in  minimum  specifications  define  the  required 
degrees  of  the  various  specific  abilities. 

III.  TESTS. — When  minimum  specifications  are  used  as  criteria  for 
selecting  and  assigning  men  who  already  have  occupational  skill, 
some  means  must  be  provided  for  quickly  and  accurately  determining 
what  kinds  and  degrees  of  specific  ability  are  possessed  by  the  can- 
didate. 

The  best  tests  are  those  by  which  the  candidate's  abilities  and  profi- 
ciencies are  determined  most  accurately  with  the  least  expenditure  of 
time  and  energy.  To  accomplish  this  the  candidate's  performance 
should  leave  a  record  that  shows  obviously  his  degree  of  proficiency 
or  deficiency  in  one  or  more  of  the  required  abilities.  Such  tests  are 
called  objective  tests  to  distinguish  them  from  examinations  or  inter- 
views, the  results  of  which  depend  mainly  on  the  personal  or  sub- 
jective judgment  of  the  examiner.  Hence — > 

Objective  tests  are  devices  for  determining  quickly  and  without 
personal  bias  what  kinds  and  degrees  of  specific  ability  are  possessed 
by  individuals.  Objective  tests  are  of  two  general  kinds : 

Aptitude  tests,  which  reveal  whether  a  candidate  has  the  kinds  of 
specific  abilities  required  for  a  given  grade  or  rating;  and 

Tests  of  proficiency,  which  indicate  relative  degrees  of  proficiency 
for  a  specific  ability  or  a  particular  group  of  specific  abilities. 

Tests  of  proficiency  make  possible  a  rapid  classification  of  men  in 
their  order  to  excellence  with  regard  to  the  specific  abilities  tested. 
In  order  to  use  them  as  a  measure  of  proficiency,  a  critical  score  must 
be  chosen  to  mark  the  dividing  line  between  proficiency  and  defi- 
ciency. The  selection  of  the  critical  score  requires  giving  the  test  to  a 
number  of  men  whose  relative  proficiency  has  been  judged  by  several 
competent  observers  over  an  adequate  period  of  observation.  The 
validity  of  tests  of  proficiency  thus  rests  on  the  judgment  of  compe- 
tent observers.  Their  advantage  lies  in  the  fact  that  they  enable  an 
officer  to  secure  quickly  a  proficiency  classification  which  is  as  good  or 
better  than  he  could  secure  in  weeks  by  observation  of  the  men  on 
the  job. 

This  process  of  determining  the  critical  score  that  marks  the  divid- 
ing line  between  proficiency  and  deficiency  for  a  given  grade  or 
rating  is  called  standardization  of  the  test.  Hence — 


6  THE   TECHNIQUE   OF   AKMY   TRAINING. 

A  standardised  test  is  an  objective  test  in  which  the  critical  score 
required  for  each  grade  or  rating  has  been  reliably  determined. 

IV.  INSTRUCTION  UNITS. — When  minimum  specifications  are  used 
as  an  objective  for  training  men  to  qualify  for  any  given  grade  or 
rating,  green  or  partially  qualified  men  must  be  selected  to  take  the 
work  and  suitable  courses  of  instruction  must  be  prepared.  The 
essential  personal  characteristics  mentioned  in  minimum  specifica- 
tions furnish  the  guide  for  selecting  men  best  suited  temperamentally 
for  the  work.  The  skill  and  knowledge  specifications  define  the 
various  kinds  of  proficiency  that  must  be  acquired  by  training.  Ex- 
perience indicates  that  the  preparation  of  a  course  that  achieves 
thoroughness  and  speed  necessitates,  first,  the  analysis  of  the  re- 
quired skills  and  knowledge  into  operations  or  elements  each  of 
which  is  a  good  unit  of  instruction  and,  second,  the  combination  of 
these  instruction  units  into  a  practical  school  program. 

The  requirements  of  any  grade  or  rating  may  be  analyzed  in  an 
unlimited  number  of  ways.  Efficiency  of  instruction  depends  in 
large  measure  on  how  the  analysis  is  made.  Experience  indicates 
that  a  logically  coherent  analysis  into  what  may  by  analogy  be  called 
points,  lines,  and  planes  is  inexpedient  for  instruction  of  the  sort 
of  soldier  the  Army  actually  has  to  train.  For  purposes  of  instruc- 
tion it  is  more  expedient  to  break  up  the  requirements  for  pro- 
ficiency into  fragments,  each  of  which  must  obviously  be  mastered 
in  order  to  become  proficient,  because  it  occurs  frequently  in  sub- 
stantially the  same  form,  either  alone  or  in  combination  with  other 
similar  fragments,  in  practical  work.  Such  natural  fragments  of  the 
work  required  in  a  grade  or  rating  are  called  unit  operations. 

A  unit  operation  is  a  group  of  manipulative  processes  which  is 
large  enough  to  make  a  good  instruction  unit  and  which  occurs  fre- 
quently in  substantially  the  same  form,  either  alone  or  in  combina- 
tion with  other  unit  operations,  in  practical  work. 

Related  to  the  technique  of  performing  the  unit  operations  there 
are  usually  a  number  of  auxiliary  facts  which  a  man  must  know  if 
he  is  to  be  really  proficient.  If  these  facts  are  not  brought  to  his  at- 
tention in  the  process  of  doing  the  unit  operations,  they  should  be 
presented  to  him  by  means  of  questions  in  class  discussions  or  by 
means  of  required  study  of  reference  books.  Groups  of  such  auxiliary 
facts  are  called  information  topics.  Hence — 

An  information  topic  is  a  group  of  related  facts,  the  mastery  of 
which  is  essential  to  proficiency  in  a  given  grade  or  rating. 

A  complete  analysis  of  the  requirements  of  a  minimum  specifica- 
tion is  a  list  of  both  the  unit  operations  a  candidate  must  be  able  to 
do  and  the  additional  information  topics  he  must  know.  Such  a  list 
is  called  the  operations  index. 


INTRODUCTION.  7 

V.  INSTRUCTION  MANUALS  are  of  two  kinds,  students'  manuals  and 
instructors'  guides. 

The  students^  manuals  consists  of  three  essential  parts,  namely : 

1.  The  operations  index,  containing  the  unit  operations  and  infor- 
mation topics  into  which  the  requirements  for  a  grade  or  rating  have 
been  analyzed  for  purposes  of  instruction. 

2.  Operation  sheets  give  in  natural  order  directions  for  performing 
the  unit  operations  mentioned  in  the  operations  index,  together  with 
the  necessary  drawings,  illustrations,  and  list  of  significant  questions. 

The  objective  of  the  operation  sheet  is  to  guide  the  student  to  rapid 
acquisition  of  correct  technique  in  those  manipulative  operations 
which  are  automatisms  in  a  skilled  workman.  The  directions  are 
clear,  concise,  and  follow  the  natural  order  of  procedure  established 
in  standard  practice.  The  questions  are  generally  of  such  nature  that 
they  can  be  answered  by  observation  or  a  little  experimenting  while 
doing  the  work  itself.  They  do  not  lead  far  afield  for  information 
not  essential  to  quick  mastery  of  correct  manipulative  technique. 

3.  Information  sheets  contain  brief  discussions  of  the  information 
topics  mentioned  in  the  operations  index,  together  with  the  necessary 
drawings,    illustrations,    significant    questions,    and    references    for 
further  study. 

The  discussions  in  information  sheets  are  clear,  concise,  and  lim- 
ited to  information  really  essential  to  proficiency  in  technique.  The 
questions  guide  the  student  to  see  relationship  among  the  facts 
learned  and  ultimately  to  discover  general  principles  involved. 

In  some  cases  it  is  most  expedient  to  use  each  unit  operation  as  a 
separate  assignment  or  job.  In  other  cases  it  is  better  to  assign 
men  to  jobs  that  involve  several  of  the  unit  operations.  In  the  latter 
case  it  is  convenient  to  use  a — 

Job  assignment  sheet,  which  is  a  blank  containing  spaces  for — 

(a)  A  concise  definition  of  the  job. 

(5)   Specifications  of  detail. 

(c)  Sketch  or  drawing. 

(d)  List  of  unit  operations  in  the  order  to  be  performed. 

(e)  Significant  questions  by  the  instructor. 
(/)  Answers  written  in  by  the  students. 

The  instructors'*  guide  contains  suggestions  for  instructors  con- 
cerning such  matters  as: 
Equipment  and  shop  set-up. 
Securing  productive  work  for  classes. 
Prerequisites  for  admittance  to  the  work. 
Selection  of  type  jobs. 

Organizing  productive  jobs  to  cover  all  unit  operations  required. 
Circulation  of  students  among  jobs. 
Preliminary  exercises,  drills,  information,  and  problems. 


8  THE   TECHNIQUE    OF   ARMY   TRAINING. 

Records,  grades,  standards,  and  tests. 

VI.  RATINGS. — The  instructor's  estimate  of  the  excellence  of  the 
student's  performance  is  entered  on  the  rating  card.    The  rating  card 
(Form  758,  A.  G.  O.,  "Proficiency  Rating  in  Vocational  Training") 
contains  the  operations  index  on  the  left  and  a  series  of  10  vertical 
blank  columns  on  the  right.     When  a  student  has  completed   an 
operation,  the  instructor  draws  a  horizontal  line  opposite  the  opera- 
tion and  of  such  length  as  to  indicate  the  student's  proficiency.    The 
horizontal  lines  are  gradually  lengthened  as  practice  increases  profi- 
ciency.   At  the  end  of  the  course  the  rating  card  shows  graphically 
which  of  the  operations  have  been  done  and  what  degree  of  pro- 
ficiency has  been  attained  in  each.    A  brief  inspection  of  the  card 
enables  an  officer  to  determine  what  grade  of  work  the  man  is 
qualified  to  do.     (Cf.  Special  Regulations  121,  Apr.  8,  1921.) 

Standardized  tests,  when  available,  are  used  by  instructors  as  more 
accurate  means  of  measuring  progress  and  determining  proficiency. 
Such  tests  are  also  useful  for  higher  authority  in  appraising  results 
of  instruction  and  checking  proficiency.  A  standardized  test  may  be 
constructed  to  measure  proficieny  in  one  operation  listed  in  the  opera- 
tions index  or  it  may  be  designed  to  measure  proficiency  in  the  course 
as  a  whole. 

VII.  TABLES  OF  REQUIRED  TIME  FOR  TRAINING. — After  the  work  de- 
scribed in  the  preceding  six  sections  has  been  finished,  the  complete 
solution  of  the  problem  requires  a  determination  of  the  average  time 
required  for  an  average  green  man  to  qualify  under  an  average 
instructor  for  a  given  grade  or  rating.    In  other  words,  it  is  neces- 
sary to  know  whether  it  takes  200  or  400  hours  of  practice  and  in- 
struction for  a  man  who  possesses  the  required  personal  character- 
istics to  qualify  as  to  skill  and  knowledge. 

This  data  must  be  secured  by  experiment  with  as  large  a  number 
of  men  as  is  possible.  It  will  take  several  years  to  make  it  accurate. 
It  is  possible  within  a  few  months  to  set  upper  and  lower  limits  and 
to  decree  that  any  man  who  can  not  qualify  for  a  given  rating  in, 
say,  200  hours,  had  better  be  assigned  elsewhere.  When  this  data  is 
secured,  a  training  schedule  can  be  constructed  which  will  make  it 
possible  to  set  the  date  on  which  any  specified  number  of  men  prop- 
erly qualified  for  any  rating  can  be  delivered. 

VIII. — The  radio  operator  has  been  selected  as  an  illustration  of 
the  procedure  described  above  because  this  type  of  specialist  is  com- 
mon to  all  combat  arms.  The  steps  in  the  production  of  the  necessary 
instruction  aids  are  presented  in  the  following  order : 

1.  Minimum  specifications  for  the  third,  the  second,  and  the  first 
class  operator. 

2.  Operations  index  (complete  for  all  classes  of  operator). 

3.  Operation  sheets  (2  samples  from  students'  manual). 


MINIMUM   SPECIFICATIONS   FOR  EADIO   OPERATORS.  9 

4.  Information  sheets  (1  sample  from  students'  manual). 

5.  Instructors'  guide  (3  sections). 

6.  Tests  of  proficiency  (3  samples). 

MINIMUM    SPECIFICATIONS    FOR    RADIO   OPERATORS. 

THIRD  CLASS. 

Skill. — Transmit  and  receive  in  International  Code  15  code  groups 
of  5  letters  each  per  minute  for  3  minutes,  transcribing  received  sig- 
nals with  pen  or  pencil  in  printed  characters  with  a  maximum  of 
6  erroneous  letters.  Make  properly  the  prescribed  splices  and  ties 
of  signal  types  of  wire.  Perform  the  cycle  of  operations  necessary  to 
effectively  obtain  and  terminate  a  telephone  connection.  Change  the 
batteries  in  any  type  of  field  telephone.  Set  up  and  make  the  neces- 
sary connection  for  the  operation  of  all  radio  sets  furnished  his  par- 
ticular arm.  Make  necessary  adjustments  for  the  proper  tuning  and 
operation  of  all  radio  sets  furnished  his  particular  arm.  Test  and 
care  of  storage  batteries. 

Knowledge. — Working  knowledge  of :  The  different  parts  of  trans- 
mitting and  receiving  apparatus  of  all  radio  sets  used  by  his  par- 
ticular arm.  Batteries  furnished  for  radio  sets  used  by  his  particu- 
lar arm.  Radio  procedure,  standard  abbreviations  and  conventional 
signals.  Standard  message  blank.  Number  of  letters  or  numerals 
in  code  groups  used  in  the  radio  message  of  his  arm. 

Attain  a  minimum  of  75  per  cent  on  the  Army  examination  for 
operators,  third  class. 

Personal. —  (a)  Required:  General  standards  of  a  private.  Audi- 
tory acuity — 20/20,  Army  test.  Good  civil  or  service  record.  Intel- 
ligence, 45  points,  Army  alpha  test. 

(£)  Desired:  Sense  of  rythm.  Good  memory  span.  Ability  to 
concentrate. 

SECOND  CLASS. 

Skill. — That  required  of  third  class  radio  operators  and  the  fol- 
lowing : 

Classroom  test :  Transmit  and  receive  in  International  Code  18  code 
groups  of  5  letters  each  per  minute  for  3  minutes,  transcribing 
received  signals  with  pen  or  pencil  in  printed  characters  with  a  maxi- 
mum of  4  erroneous  letters. 

Message  and  procedure  test  (on  table  nets  or  sets  in  the  field) : 
Receive  two  coded  tactical  messages  from  a  message  center,  each 
composed  of  20  code  groups  of  5  letters  each,  required  to  complete 
the  preamble  according  to  the  directions  written  on  the  message,  and 
transmit  them  to  the  designated  receiving  stations  and  obtain  receipt 


10  THE   TECHNIQUE   OF   ARMY   TRAINING. 

in  10  minutes.  Receive  two  coded  tactical  messages,  each  composed 
of  20  code  groups  of  5  letters  each,  from  a  designated  transmit- 
ting station  and  prepare  them  for  delivery  to  message  center  with 
proper  interpretation  of  procedure  signals.  Code  a  20-word,  of  5 
letters  each,  radio  service  message,  in  radio  service  code,  correctly  in 
5  minutes.  Diagnose  trouble  and  make  ordinary  repairs  on  all  radio 
sets  used  by  this  particular  arm. 

Knowledge. — Attain  a  minimum  of  To  per  cent  on  the  Army  exami- 
nation for  operators,  second  class. 

A  working  knowledge  of:  Different  parts  of  transmitting  and 
receiving  apparatus  of  radio  sets  issued  his  arm  of  the  service.  The 
radio  organization  of  a  combat  division.  The  panel  code. 

FIRST  CLASS. 

Skill. — That  required  of  a  second-class  radio  operator  and  the  fol- 
lowing : 

Classroom  test:  Transmit  and  receive  in  International  Code  22 
code  groups  of  5  letters  each  per  minute  for  3  minutes,  transcribing 
received  signals  with  pen  or  typewriter  with  a  maximum  of  2  erro- 
neous letters. 

Message  procedure  test :  Acting  as  chief  operator  on  a  net  control 
station  in  a  net  of  three  or  more  stations  required  to  clear  the  fol- 
lowing traffic:  One  message  for  station  outside  net.  Two  messages 
for  secondary  stations  in  his  net.  An  important  message  which  a 
secondary  station  desires  to  transmit. 

Knowledge. — A  working  knowledge  of:  All  sets  issued  by  the 
Signal  Corps  within  an  army.  The  radio  organization  of  an  army. 

Attain  an  average  of  75  per  cent  on  an  Army  examination  for 
operator,  first  class. 

RADIO  OPERATORS  OPERATIONS  INDEX. 

UNIT  OPERATIONS. 
SECTION  I. 

1.  Code  practice,  block  No.  1. 

2.  Code  practice,  block  No.  2. 

3.  Code  practice,  block  No.  3. 

4.  Code  practice,  block  No.  4. 

5.  Code  practice,  block  No.  5. 

6.  Code  practice,  block  No.  6. 

7.  Code  practice,  block  No.  7. 

8.  Receiving  and  transmitting  practice. 

9.  Operate  "  break-in  "  table  nets  under  radio  procedure  rules. 


RADIO   OPERATORS   OPERATIONS   INDEX.  11 

10.  Operate    "  nonbreak-in "    table    nets    under    radio    procedure 
rules. 

11.  Operate  nets  on  sets  in  a  building. 

12.  Operate  field  nets. 

13.  Operate  field  nets  under  varying  tactical  conditions. 

14.  Solve  chief  operator's  problems  on  field  nets. 

15.  Solve  net  command  station  problems  on  field  nets. 

SECTION  II. 

16.  Make  splices  and  ties  in  field  wire. 

17.  Connect  and  operate  field  telephones. 

18.  Test  and  change  batteries  in  various  types  of  field  telephones. 

19.  Connect  and  test  primary^  batteries  used  in  radio  sets. 

(a)  Series  and  parallel  connections  with  specified  sets. 

(b)  Determine  voltage  per  battery. 

20.  Connect  and  test  secondary  batteries  used  with  radio  sets.    Use 
both  series  and  parallel  connections  with  specified  sets. 

21.  Set  up  and  operate  SCR-105  sets. 

22.  Locate  and  repair  troubles  on  SCR-105  sets. 

23.  Make  adjustments  on  the  SCR-105  sets. 

24.  Set  up  and  operate  SCR-130  set. 

25.  Locate  and  repair  troubles  on  SCR-130  sets. 

26.  Test  tubes  for  SCR-130  set. 

27.  Set  up  and  operate  SCR-77  set. 

28.  Locate  and  repair  minor  troubles  in  SCR-77  set. 

29.  Calibrate  SCR-77  set. 

30.  Test  tubes  for  SCR-77  set. 

INFORMATION  TOPICS. 
SECTION  I. 

1.  Correct  position  at  key  and  grip  of  key. 

2.  Radio  procedure. 

3.  Procedure  for  handling  message  blanks. 

4.  Procedure  for  handling  traffic  on  "  break-in  "•  table  nets. 

5.  Procedure  for  handling  traffic  on  "nonbreak-in"  nets. 

6.  Procedure  for  handling  traffic  on  field  nets. 

7.  Problems  chief  operators  must  solve. 

8.  Problems  net  command  stations  must  solve. 

SECTION  II. 

9.  Types  of  wire  and  splices. 

10.  Connecting  up  and  operating  field  telephone  and  testing  and 
changing  batteries. 


12  THE   TECHNIQUE   OF   ARMY   TRAINING. 

11.  Primar}^  batteries  used  in  radio  sets. 

12.  Series  and  parallel  connections  of  batteries. 

13.  Ohm's  law  and  use  of  D.  C.  measuring  instruments. 

14.  Secondary  batteries  used  with  radio  sets. 

15.  Care  and  testing  of  batteries  by  radio  operators  in  the  field. 

16.  Ohm's  law  applied  to  batteries  connected  in  series  and  parallel. 

17.  Antenna  systems. 

18.  Use  of  crystal  detectors  in  the  receiving  circuit. 

19.  Method  of  locating  and  repairing  troubles  on  SCR-105  set. 

20.  Induction  as  illustrated  in  the  buzzer  transformer. 

21.  The  spark  gap  in  SCR-105  set. 

22.  Adjustments  on  the  SCR-105  set. 

23.  Method  of  determining  wave  length  by  wave  meter. 

24.  Power  equipment  with  SCR-130  set. 

25.  Condensers  used  in  SCR-130  set. 

26.  Simple  vacuum  tube  amplifier  and  its  modifications  in  the 
SCR-130  set. 

27.  Method  of  tuning  SCIt-130  set  for  resonance. 

28.  Comparison  of  grounds  and  counterpoises  in  the  case  of  the 
SCR-130  set. 

29.  Methods  of  locating  and  repairing  troubles  on  SCR-130  set. 

30.  Methods  of  testing  tubes  in  SCR-130  set. 

31.  Methods  of  locating  and  repairing  minor  troubles  in  SCR-77 
set. 

32.  Methods  of  calibrating  SCR-77  set. 

33.  Methods  of  testing  tubes  on  SCR-77  set. 

34.  Difference  in  methods  of  detecting  signals  in  the  SCR-130 
and  SCR-77  sets  (autodyne  and  heterodyne). 

RADIO  OPERATORS'  UNIT  OPERATION  NO.  1. 

BLOCK  I. 

1.  Learn  the  symbols  for  the  following  letters  (International  Morse 
Code)  : 

A«  —  N— • 

E  •  T  — 

I  .  .  R  .  —  • 

S  •  •  •  L  •  •••  •  • 

H  •  •  •  • 

2.  Practice  on  the  following  list  of  words  until  each  of  the  symbols 
are  mastered.     Each  letter  should  be  sent  or  received  at  top  speed 
of  not  less  than  at  the  rate  of  20  words  per  minute.    At  first  a  greater 
space  may  be  made  between  each  letter  or  between  each  word,  so  that 
at  first  only  a  few  words  will  be  sent  per  minute. 

Question:  1.  Why  is  it  better  to  send  or  receive  each  letter  at  maxi- 
mum speed  from  the  very  beginning? 


RADIO  OPERATORS  UNIT  OPERATION  NO.  1. 


13 


O.  S.  2. 


air 

attain 

attire 


GROUP  1 .— AENST. 


an 

ate 

net 

sent 

tent 

ant 

assent 

nest 

sane 

test 

as 

attest 

neat 

sense 

tea 

ass 

eat 

sat 

tan 

tease 

at 

east 

set 

ten 

taste 

GBOUP  2. — Add  "  R  "  to  Group  1. 


are 

ear 

near 

tar 

rat 

art 

earn 

star 

tare 

ran 

anest 

err 

start 

tares 

rare 

rent 

GROUP  3. — Add  "  I  "  to  Group  2. 


entire 

nit 

sin 


sit 

saint 

sister 


stir 

stair 

stain 


GROUP  4. — Add  "  L  "  to  Group  3. 


GROUP  5.— Add  "  H  "  to  Group  4. 


GROUP  6. — Review. 


rise 

rinse 

rite 


all 

sales 

sail 

last 

listen 

ale 

slat 

tail 

least 

learn 

ail 

slate 

tale 

less 

latent 

eel 

slant 

rail 

latter 

lantern 

sale 

slain 

rill 

little 

late 

salt 

snail 

hat 

hasten 

hit 

shin 

than 

hate 

hare 

hill 

shine 

these 

hall 

hen 

either 

shrine 

that 

hail 

her 

neither 

shatter 

thin 

hair 

here 

rather 

the 

then 

has 

hear 

she 

their 

thirst 

haste 

hell 

share 

there 

this 

air 

enter 

in 

list 

sail 

all 

entire 

interest 

listen 

salt 

an 

hair 

is 

little 

sat 

are 

has 

it 

near 

sea 

art 

hat 

last 

neither 

seat 

as 

he 

late 

nest 

see 

at 

hear 

learn 

nine 

seen 

ear 

heart 

least 

rain 

sell 

earth 

heat 

led 

raise 

sent 

ease 

her 

less 

ran 

set 

east 

here 

let 

rather 

shall 

eat 

hill 

letter 

real 

she 

either 

his 

lie 

rest 

shine 

else 

ill 

line 

rise 

sir 

14 


THE   TECHNIQUE   OF   ARMY   TRAINING. 


sister 

sit 

star 

start 

still 

street 

tail 


tale 

tall 

taste 

tea 

tear 

tell 

ten 


than 

that 

the 

thee 

their 

then 


there 

these 

thin 

this 

thru 

tie 


till 

tire 

train 

tree 

trust 

truth 


A 


SQUARE    KNOT 


SEIZED    WITH  COPPER  WIRE 


RUBBER    TAPE 


FRICTION    TAPE 


O.  S.  No. 


FIG.  1. 

UNIT  OPERATION  NO.  16. 
MAKING  SPLICES  AND  TIES  IN  FIELD  WIRES. 

Directions. 

1.  With  a  pair  of  pliers  cut  a  1-foot  section  of  field  wire  from  the 
piece   issued. 

2.  Cut  off  about  3  inches  of  one  wire  at  each  end  of  the  twisted 
pair. 


RADIO   OPERATORS   INFORMATION    TOPICS.  15 

3.  Remove  about  2  inches  of  the  insulation  from  all  four  ends  by 
squeezing  the  insulation  with  the  pliers,  cutting  the  insulation  with 
a  circular  motion  by  means  of  the  knife  or  pliers  and  peel  off  the  in- 
sulation. 

4.  Tie  a  square  knot.     (See  fig.  1  (a).) 

5.  Seize  the  joint  with  No.  20  copper  wire,  taking  care  that  the 
ends  of  the  steel  wire  lie  flat  against  the  main  wire.     (See  fig.  1 

(b).) 

6.  Wrap  with  rubber  tape,  starting  at  one  end,  overlapping  the  in- 
sulation by  1  inch.     Wrap  in  one  direction,  ending  about  1  inch  be- 
yond insulation  at  the  other  end.     (See  fig.  1  (c).) 

7.  Wrap  at  joint  with  friction  tape  in  the  reverse  direction.     (See 

fig.  i  (d>.) 

8.  Repeat  this  series  of  operations  with  outpost  wire. 

Questions. 

1.  Would  removing  1  inch  of  insulation  permit  tying  the  knot  ? 

2.  Why  not  use  iron  wire  for  seizing  ? 

3.  Can  a  joint  be  made  by  lapping  the  two  wires  side  by  side  and 
then  seized,  be  pulled  apart  easily? 

4.  Can  a  joint  made  with  a  square  knot  and  seized,  be  pulled 
apart  ? 

RADIO  OPERATORS  INFORMATION  TOPICS. 

SECTION  II,  No.  9. 

Types  of  wires  and  splices. — There  are  three  common  types  of  wire 
in  use  in  a  combat  division:  (1)  Twisted  pair  field  wire,  (2)  outpost 
wire,  (3)  outside  distributing  17-2  wire. 

1.  Telephone  circuits,  wherever  possible,  are  made  metallic  and 
not  grounded.     In  a  metallic  circuit  there  is  a  wire  going  to  and  a 
wire  returning  from  the  telephone.     These  wires  are  usually  twisted 
together  and  commonly  called  "  twisted  pair."     In  a  grounded  circuit 
one  wire  is  all  that  is  necessary  between  two  stations,  the  earth  form- 
ing the  return  path. 

2.  The  poor  service  offered  by  a  grounded  telephone  circuit  and 
the   possibility   of  the  enemy  readily  intercepting  messages   when 
transmitted  over  such  a  system  make  this  method  prohibitive. 

3.  Twisted  pair  field  wire  (type  W-40)  consists  of  10  steel  wires, 
12  mills   (0.012  inch)   in  diameter,  twisted  about  one  copper  wire 
28  mills  in  diameter,  the  whole  being  covered  with  rubber  insulation 
and  cotton  braid.     This  wire  will  usually  be  found  on  circuits  laid 
by  the  division  signal  company  and  sometimes  by  infantry  brigade 
communication  platoons  and  by  all  artillery  units. 


16  THE  TECHNIQUE   OF   ARMY   TRAINING. 

4.  Twisted  pair  outpost  wire  (type  W-44)  is  lighter  than  field 
wire  and  has  three  steel  and  three  bronze  wires  each  13  mils  in 
diameter  twisted  about  one  bronze  wire  14  mils  in  diameter  and 
covered  with  rubber  insulation  and  paraffined  cotton  braid.     This 
wire  is  used  by  all  infantry  communication  platoons. 

5.  Outside  distributing  wire  (17-2),  which  means  No.  17  Brown  & 
Sharpe  wire  gauge  2  conductors,  is  used  in  commercial  telephone 
installation,  and  no  doubt  would  be  furnished  to  the  Army  in  large 
quantities  in  case  of  hostilities,  due  to  its  ease  of  manufacture.    This 
wire  is  used  by  the  division  signal  company  and  artillery  units. 

6.  Splices  in  all  three  of  the  above-mentioned  wires  are  important 
to  a  radio  operator,  for  in  operations  he  would  have  a  field  telephone 
installed  at  or  near  his  radio  apparatus  and  would  be  called  upon 
to  repair  broken  connections  near  his  station  or  perhaps  to  actually 
install  the  telephone. 

7.  Splices  in  twisted  pair  should  be  staggered. 

8.  The  most  satisfactory  splice  for  field  wire  is  made  by  stripping 
the  ends  of  the  wire  for  about  2  inches,  then  tying  the  bare  ends  in 
a  square  knot  and  seizing  or  wrapping  the  ends,  so  that  they  will  lie 
flat,  with  a  piece  of  soft  copper  wire,  No.  18  or  No.  20,  about  6 
inches  long,  and  then  cover  with  rubber  and  friction  tape.    If  wire 
for  seizing  is  not  available,  the  steel  wires  can  be  cut  away,  leaving 
enough  of  the  copper  wire  to  seize  the  joint.    When  it  is  impossible 
to  use  either  of  these  two  methods,  great  care  must  be  used  to  make 
a  tight  knot  and  wrap  it  securely  with  tape,  because  the  springy 
character  of  the  steel  wires  may  cause  their  ends  to  puncture  the 
tape  insulation  and  cause  a  ground  which  prevents  talking  over  the 
telephone. 

1.  Why  are  the  joints  in  twisted  pairs  staggered? 

2.  What  is  the  purpose  of  the  rubber  tape  ? 

3.  What  is  the  purpose  of  the  friction  tape? 

4.  What  is  the  purpose  of  the  copper- wire  seizing  ? 

RADIO  OPERATORS  INSTRUCTOR'S  GUIDE. 

SHOP  AND   CLASSROOM   SET-UP CODE  PRACTICE  EQUIPMENT. 

A.  Break-in  table  nets,  for  use  in  training  operators  in  transmis- 
sion and  reception  and  for  "  break-in  nets."    Equipment  required : 

1.  A  switchboard  (a  telegraph  switchboard  is  preferable,  but  an 
improvised  one  can  be  easily  made) . 

2.  A  source  of  tone  supply  must  be  provided.     A  power  buzzer 
from  a  T.  P.  S.  set  may  be  used  or  a  five  to  nine  hundred  cycle  motor 
generator  set  may  be  used  or  a  vacuum  tube  oscillator  or  a  field 
buzzer  will  answer  this  purpose  very  well. 


RADIO   OPEEATOES  INSTRUCTOR'S   GUIDE. 


17 


3.  Telegraph  keys  and  head  sets  for  each  student's  position  de- 
sired. 

4.  Table  or  tables  for  mounting  keys  and  head  sets,  preferably 
separated  by  a  high  board  down  the  center  and  partitions  between 
the  operators. 

5.  Two  and  three  stations  on  each  circuit,  which  can  be  connected  by 
means  of  the  switchboard  to  form  a  net  of  two,  three,  four,  or  more 
stations  as  may  be  desired. 

6.  The  stations  on  any  one  circuit  should  not  be  adjacent,  so  that 


riead  Phones 


Condenser 

FIG.  2. 

operators  in  the  same  net  can  not  talk  to  each  other  or  see  each 
other's  work,  but  must  work  through  their  own  key  and  head  set. 

7.  Figure  2  illustrates  one  method  for  forming  the  circuits  for 
"break-in  nets."    This  method  has  the  following  disadvantages: 

(a)  Eequires  a  separate  source  of  tone  supply  for  each  circuit. 
(&)  Field  buzzer  and  century  buzzers  get  out  of  adjustment  and 
the  tone  is  not  constant. 

(c)  Separate  circuits  can  not  be  thrown  together  easily. 

8.  Figure  3  shows  a  much  more  flexible  method  than  the  one  de- 
scribed under  7.    This  has  a  common  sound  of  tone  supply. 


Power*  Buzzer 


'Single 
Positions 


Transformer 

FIG.  3. 

A  suitable  transformer  can  be  made  by  using  the  core  of  a  Western 
Electric  25-A  telephone  repeater  coil  upon  which  is  wound  300  turns 
of  No.  22  D.  C.  C.  magnet  wire  to  form  the  primary.  Five  turns  for 
each  secondary  circuit  will  give  sufficient  voltage  to  supply  a  tone  of 
proper  loudness  to  one  head  set  when  100  volts  is  applied  to  the 
primary.  Ten  turns  are  required  for  two  head  sets  in  series  and  15 
turns  for  three  head  sets  in  series. 
85047°— 22 2 


18 


THE   TECHNIQUE   OF   ARMY  TRAINING. 


Figure  4  is  a  diagram  which  shows  the  actual  connections  of  the 
secondary  of  the  transformer,  the  switchboard  and  two  head  sets. 


FIG.  4. 

Figure  5  shows  the  method  of  arranging  circuits  so  that  operators 
can  not  talk.    Assuming  that  there  are  six  circuits  with  two  student 
positions  1  and  1,  2  and  2,  etc.,  on  each  circuit. 

B.  " Nonbreak-in  table  nets" — Equipment  same  as  in 
"  break-in  "  nets,  with  double  pole,  double  throw  switch, 
added  for  each  student's  position. 

Figure  6  shows  the  connections  when  the  student's 
change-over  switch  is  thrown  to  transmit,  and  figure  7 
shows  the  switch  on 
the  receiving  posi- 
tion. Three  wires 
must  be  run  to  each 
student's  position. 

Figure    8    shows 


z 

1 

4 

3 

6 

5 

1 

^ 

3 

4 

5 

6 

FIG.  G. 


FIG  5.  e  wrng 

of  student's  position. 
In  connecting  several  lines  on 
the  board  to  form  a  net  the 
board  is  so  plugged  that  the 
lines  are  in  parallel.  One  line 
will  not  operate  by  itself.  When 
several  switches  are  in  a  net  on  "  receive "  their  head  sets  are  in 
parallel  across  the  line  and  those  on  "transmit"  have  their  trans- 
former secondaries  and  keys  individually  in  series  and  these  series 
in  parallel  across  the  line. 

Thus,  if  two  stations  in  the  same  net  transmit  at  the  same  time,  each 
of  these  will  hear  nothing,  but  stations  on  "  receive  "  will  hear  a  com- 


RADIO   OPERATORS  INSTRUCTOR'S   GUIDE. 


19 


bination  of  both  transmissions.    This  is  actually  what  takes  place  in 
the  field  on  sets  under  similar  circumstances. 

UNIT  OPERATION  NO.    1,  CODE  PRACTICE,  BLOCK  NO.   1. 

1.  In  teaching  the  International  Morse  Code,  each  letter,  at 
top  speed  of  about  20  words  of  5  letters  each  per  minute,  has 
a  distinct  rythm  peculiar  to  itself.  The  speed  is  so  fast  that 
it  becomes  impossible 
actually  to  count  the  dots 
and  dashes.  "  S  "  is  "  S  " 
because  it  has  three  dots, 
and  "  H  "  is  "  H  "  because 
it  has  four  dots.  "  R  "  is 
"  R "  because  it  has  dot, 
dash,  dot;  but  they  can 
not  be  actually  counted, 
therefore  the  characteris- 
tic rythm  for  each  letter 
must  be  learned  and  prac- 
ticed until  it  becomes  a 
habit  or  an  automatism. 

It  is  apparent,  therefore,  that  every  letter  should  be  learned  at  top 
speed  from  the  very  first. 

With  the  beginner,  the  space  between  letters  may  be  lengthened, 
also  the  space  between  words  should  be  lengthened;  thus  the  actual 
number  of  words  that  can  be  sent  and  received  per  minute  will  be 


FIG.  7. 


reduced,  although  the  speed  at  which  each  letter  is  sent  or  received  is 
top  speed. 

As  the  student  becomes  more  and  more  familiar  with  each  rythm 
characteristic  of  each  letter  and  numeral,  then  the  space  between 


20  THE  TECHNIQUE  OF  ARMY  TRAINING. 

letters  and  words  may  be  gradually  reduced  until  the  desired  speed  in 
words  per  minute  has  been  acquired. 

2.  A  schedule  should  be  arranged  to  permit  code  practice  for  6 
periods  of  20  minutes  each,  distributed  over  the  working  day.  The 
other  period  may  be  devoted  to  the  study  of  the  apparatus  and  dif- 
ferent installations  called  for  in  the  other  unit  operations  or  a  study 
of  the  information  sheets  and  other  references. 

The  student  will  be  taught  the  symbols  for  each  of  the  letters  given 
in  the  student's  manual,  block  1,  group  1.  Each  of  these  letters  should 
be  sent  repeatedly  at  top  speed  until  the  student  learns  the  rythm  of 
each  letter. 

In  group  2  an  additional  letter,  "  I,"  is  added.  This  should  be 
explained  and  sent  to  the  student  until  the  rythm  becomes  familiar. 
Then  have  the  student  practice  on  the  words  given  in  group  2,  in 
which  the  new  letters  in  each  word  appear,  together  with  letters 
already  mastered  in  group  1. 

In  a  similar  manner  give  the  other  letters  in  groups  3  to  6. 

An  examination  is  to  be  given  by  the  instructor  for  promotion  into 

block  2. 

UNIT  OPERATION  NO.  10. 

MAKING  SPLICES  AND  TIES  IN  FIELD  WIRE. 

1.  Equipment.     The  following  equipment  should  be  ready  to  issue 
to  each  student : 

One  pair  of  pliers,  6-inch  or  8-inch. 

One  electrician's  knife. 

Eight  feet  of  twisted  pair  field  wire  (type  W-40). 

Eight  feet  of  twisted  pair  outpost  wire  (type  W-44). 

Eight  feet  of  outside  distributing  wire  (17-2). 

2.  At  the  meeting  of  the  class  when  the  job  is  assigned,  exhibit  and 
describe  the  different  types  of  wire  used  in  a  division  and  what  units 
use  the  different  types.     (See  Information  Topic  No.  9.) 

3.  In  a  similar  manner,  exhibit  and  demonstrate  the  different  types 
of  splices  on  field  wire. 

4.  In  a  similar  manner,  exhibit  and  demonstrate  the  making  of  a 
splice  on  17-2  wire. 

5.  Suggested  types  of  questions  to  be  asked  the  students  for  dis- 
cussion at  preliminary  meeting : 

(1)  Why  is  it  important  to  make  a  good  mechanical  joint? 

(2)  Is  a  rat-tail  joint  a  good  joint  if  liable  to  stress? 

(3)  Why  should  stranded  conductors  not  be  spliced  in  the 
form  of  a  Western  Union  joint? 

6.  In  the  laboratory  have  each  student  make  splices  on  field  wire 
and  outpost  wire.     This  should  be  continued  until  the  student  be- 
comes proficient. 


RADIO   OPERATORS   INSTRUCTOR^   GUIDE.  21 

7.  In  a  similar  manner  have  each  student  practice  making  splices 
on  17-2  wire. 

The  student  is  sufficiently  proficient  when  he  can  make  a  satisfac- 
tory field-wire  splice  in  four  minutes  and  a  17-2  wire  splice  in  two 
minutes. 

8.  Informal  questions  should  be  asked  by  the  instructor  as  he 
makes  his  rounds  in  the  laboratory.    These  questions  should  be  de- 
signed to  help  a  man  who  is  experiencing  difficulty  in  doing  the  job 
assigned  or  who  may  need  a  clearer  understanding  of  some  phase  of 
the  job  while  doing  the  work. 

9.  After  the  job  is  completed,  the  student  or  group  of  students 
should  be  reviewed  by  the  instructor.     At  this  time  such  questions 
should  be  asked  as  are  necessary  to  lead  to  a  fuller  comprehension  of 
what  has  been  done,  to  the  end  that  the  men  utilize  as  fully  as 
possible  for  succeeding  work  the  experience  gained. 

(1)  For  what  reasons  has  the  square  knot  been  adopted  for 
this  class  of  work  rather  than  other  types? 

(2)  Would  steel  wire  be  equally  as  good  for  seizing  as  soft 
copper  wire  ? 

(3)  Would  it  have  been  just  as  satisfactory  to  have  placed  the 
friction  tape  on  first  and  then  the  rubber  tape  ? 


22 


THE   TECHNIQUE    OF   ARMY   TRAINING. 

RADIO  MESSAGE  BLANK. 

(For  tactical  use  only.) 


(For  Message  Center  Clerk) 


JACK  SON .  Message  Center. 


(code  name) 
Encoded  by  JONES 


14:21 


(time) 


Serial  No. 


.12/1/21 


(date) 


Send  this  message  to 


FIRST  DIVISION 


Have  it  repeated  back.     >/ 
Class:  Official. 


(For  Radio  Operator) 


V 
XZ2        XY7 


NR 


Station 
Called 


Station 
Calling 


Relay      Transmit    Originally 
via  to  from 


Receiving        Repeat    Type  of 
station  will       back        message 
not  acknowl- 
edge 


essage  C 
rial  No. 


Serial  No 


G 

OD 

Gr 

12 

BT 

Group  in 
Body  of  message 


Following 
groups 
sent  now 


AHWO 


LBTR 


Nr 


13:50 


DFC-4 


Writer's 
Serial  No. 

QMTV 


PDRO 


Writer's 
time 

HBJY 


FWHX 


Code 
Used 


UOTZ 


WBVN 


HDQU 


R 


Time  If  "  F  "  was  sent,  indicate      Check  in  this  space  if 

Filled  in  when  " F"  is  not  sent        transmission  time  message  can  not  be 

sent  bv  radio. 


ARMY  TEST,  RADIO  OPERATORS. 
FORM  "A" 


23 


ARMY  TEST,  RADIO  OPERATORS. 

TECHNICAL. 


vk  • 


F*M$i  •  c 
•  w/^ 


FIG.  9. 

1.  Question.  What  does  Figure  9  represent? 
Answer.  Head  receivers  for  a  radio  set. 

2.  Question.  Why  are  the  receivers  placed  the  way  they  are  ? 
Answer.  To  protect  the  diaphrams. 

3.  Question.  Why  are  they  wound  with  a  telephone  cord? 
Answer.  To  hold  the  receivers  together  during  transportation. 


^Complete  «aet 


SETTIBO  TIP  AB  "L"  ANTEKKA 


FIG.  10. 

4.  Question.  What  set  uses  the  type  of  antenna  shown  in  Figure  10  ? 
Answer.  The  SCR-105  set. 

5.  Question.  What  is  the  name  of  this  type  of  antenna  ? 
Answer.  Inverted  "  L." 


24 


THE  TECHNIQUE   OF  ARMY  TRAINING. 


6.  Question.  What  does  the  diagram  in  Figure  11  represent? 
Answer.  A  circuit  diagram  of  a  buzzer  transformer. 

7.  Question.  What  is  the  name  of  the  part  marked  "  B  "  ? 


FIG.  11. 


Answer.   (1)  Vibrator.    (2)  Armature  arm.    (3)  Buzzer. 

8.  Question.  What  is  the  name  of  the  windings  marked  "  F  "  and 
E"? 

Answer.  Primary. 

9.  Question.  What  is  the  name  of  the  windings  marked  "  S  "  ? 


FIG.  12. 


Answer.  The  secondary. 

10.  Question.  What  is  the  part  marked  "  D  "? 

Answer.  Condenser. 


ARMY  TEST,  RADIO  OPERATORS. 


25 


11.  Question.  In  Figure  12,  with  what  is  detection  of  signals  ac- 
complished in  the  circuits  shown  ? 

Answer.  A  crystal  detector. 

12.  Question.  What  is  the  purpose  of  the  buzzer  in  this  circuit  ? 
Answer.  To  find  a  sensitive  point  on  the  crystal  detector. 

13.  Question.  What  kind  of  waves  will  such  a  set  receive  ? 
Answer.    Damped  waves. 


Te(<*t>KorN«  jack 
J 


FIG.  13. 

14.  Question.  What  is  the  device  called  by  means  of  which  the  de- 
tection of  signals  is  accomplished  in  the  circuit  shown  in  Figure  13  ? 

Answer.  A  vacuum  tube. 

15.  Question.  What  is  the  purpose  of  the  grid  leak  resistance? 
Answer.  To  let  the  negative  charge  leak  off  the  grid. 

16.  Question.  What  is  the  purpose  of  the  "  BA-2  "  battery? 
Answer.  To  furnish  plate  voltage. 

17.  Question.  Of  what  set  is  Figure  14  a  circuit  diagram  ? 
Answer.  SCR-77. 

18.  Question.  Place  the  letter  "  O  "  alongside  the  oscillator  tube 
on  this  set. 

Answer.  (The  left  tube.) 

19.  Question.  What  is  the  voltage  of  the  battery  used  to  light  the 
filaments? 

Answer.  Four  volts. 

20.  Question.  In  what  circuit  is  the  key  placed  in  this  set  ? 
Answer.  In  the  plate  circuit. 

21.  Question.  Which  tube  is  used  as  a  detector  tube  ? 
Answer.  The  one  on  the  left. 

22.  Question.  Designate  with  the  letter  "A"  all  amplifier  tubes  in 
this  set. 

Answer.  The  two  on  the  right. 


26 


THE   TECHNIQUE   OF   ARMY   TRAINING. 


23.  Question.  Of  what  set  is  Figure  15  a  photograph? 
Answer.  The  SCR-105  set. 

24.  Question.  What  is  the  name  of  the  part  labeled  "K  "? 
Answer.  The  spark  gap. 

25.  Question.  How  could  the  plates  and  separators  in  this  gap  be 
removed  ? 

Answer.  By  unscrewing  the  thumb  nut  shown  in  the  picture. 


CIRCUIT  DIAGRAM 
RADIO  TRANSMITTER  &  RECEIVER  SET  TYPE  BC-9 


120-V.  40V. 


B-GRIO  BIAS  BATTCRY20-V.TYPE  BA-Z 
CH745  M.M.F  ±  10  MMf 

c2-720M.MF±  SM.M.F: 

Cy  20000  M.M.F±  1000  M.M.E 

CV  ADJUSTABLE  CONDENSER  rORW/E  LENGTH  ADJ 
OB-VARIABLE  AIR  CONDENSER  FOR  TUNING 

F  'PI  LTllRf* INDUCTANCES  4-1000 MMFCONDCNSOw) 

K-KEY-3  CONTACT 
L  -LOOP  TYPE  LP-2 
M-KILLIAMMETER  Q-IO  MILL1AMP5. 


P  x  TELEPHONES  HEADSET  TYPE  P-l  I 
R.-RESISTANCE0.50HMS.TYPE  R5-46 
R2  RESISTANCE  1.05  OHMS  TYPE  RS'44 
R3-RESI5TANCE  5000  OHMS 
RrPOTENTIOMETER  5500  OHMS 

gj  |  SWITCH  D.R5.T.(5l5S2OPEN&CLOSfT06ETMER) 

T, -TRANSFORMER  TYPE:  C-21-AUDIOTOQUENCY 
Ta-TRANSFORMER  1  TO  I  TELEPHONE 
V- VACUUM  TU6E  TYPE:  VT-I 


FIG.  14. 

26.  Question.  Under  what  circumstances  should  they  be  removed? 
Answer.  When  the  operator  observes  that  sparkling  is  confined 

to  one  or  two  points  on  the  plates,  they  should  be  removed  and 
polished  with  emery  cloth. 

27.  Question.  What  is  the  name  of  the  unit  marked  "L,"  "M," 
"N,"  "O,"  "P"? 

Answer.  The  buzzer  transformer. 

28.  Question.  What  organizations  use  this  set? 
Answer.  Infantry  regiments  and  brigades. 


ARMY  TEST,  RADIO  OPERATORS. 


27 


29.  Question.  What  is  used  for  detection  purposes  in  this  set? 
Answer.  A  crystal  detector. 

30.  Question.  Where  is  it  shown  in  this  figure? 
Answer.  In  the  upper  left-hand  corner. 


FIG 


m 


31.  Question.  What  kind  of  waves  does  this  set  transmit? 
Answer.  Damped  waves. 


28  THE    TECHNIQUE    OF   ARMY   TRAINING. 

RADIO  PROCEDURE. 

32.  Question.  The  message  shown   in   Form  "A"  has  just  been 
handed  to  a  radio  operator  for  transmission.    Fill  out  the  preamble 
of  the  message.    The  call  of  the  transmitting  station  is  XY7.    The 
call  of  the  first  division  is  XZ2. 

Answer.  (For  the  solution,  see  the  two  lines  underneath,  "  For 
Eadio  Operator,"  Form  "A.") 

33.  Question.  Indicate  with  a  check  mark  the  types  of  code  used  by 
radio  stations  in  a  division. 

(1)  AB    XY    ZE 
V(2)   127     821     783 

(3)  WHYFC    LGMNO    PQHYZ 
V(4)   176548     732145     889137 
V(5)  BQY    MRC    KNF 

(6)  B3H8    F4Z6    N2L7 
V(7)  GHBQ    RLOF    KMNP 
Answer.   (As  shown  above.) 

34.  Question.  An  operator  on  the  SCR-105  set  at  the  First  In- 
fantry has  just  connected  up  his  set  and  is  ready  for  operation.    State 
exactly  in  order  the  procedure  signals  sent  by  this  station  in  report- 
ing into  the  net.     First  Infantry  call:  MN3;  First  Brigade  call: 
(NCS)  MO7. 

Answer.  VE    MO7    V    MN3    II    ZCH 

35.  Question.  An  operator  at  First  Battalion,  First  Infantry,  has 
been  ordered  to  close  station  and  advance  with  his  battalion  com- 
mander to  new  battalion  command  post  800  yards  to  the  front. 
Write  out  all  the  procedure  signals,  in  their  order,  which  the  oper- 
ator sends.     First  Battalion,  First  Infantry  call:  BQ8.     First  In- 
fantry call :  YD9. 

Answer.  VE     YD9     V    BQ8     II    ZCJ30     AR. 

36.  Question.  An  operator  at  the  First  Battalion,  Second  Infan- 
try, is  directed  by  the  regimental  signal  officer  to  assume  command  of 
the  net.     State  in  their  order  the  procedure  signals  sent  by  first  bat- 
talion operator.     First  Battalion,  Second  Infantry  call :  XR5.    Sec- 
ond Battalion,  Second  Infantry  call :  DQ8.    Second  Infantry  (NCS) 
call:  XF2. 

Answer.  VE  XF2  V  XR5  II  ZCM  II  RSO  AR.  (XF2 
acknowledges.) 

VE  DQ8  V  XR5  II  ZCM  II  RSO  AR.  (DQ8  acknowl- 
edges.) 

37.  Question.  An  operator  at  First  Infantry  call  DB2,  is  directed 
by  the  First  Brigade  signal  officer  to  assume  command  of  the  net. 
Write  all  procedure  signals  sent  by  DB2.     First  Brigade   (NCS) 
call :  HT3.    Second  Infantry  call :  H J2.    Net  call :  DZ5. 


RADIO   PROCEDURE.  29 

Answer.  VE  DZ5  DZ55  V  DB2  DB2  II  ZCM  II  BSO 
AR. 

38.  Question.  Give  the  reply  of  HT3  in  the  above  problem. 
Answer.  VE    DB2    Y    HT3    II    R. 

39.  Question.  An  operator  call  DKT  received  a  code  message  by 
radio  from  a  station  call,  WZ1,  with  the  following  identification 
marks : 

NrS    OD    GR17    BT    Nr3    1245    DFC4. 

DKT  receipted  for  the  message  and  sent  it  to  his  message  center. 
The  message  center  asked  for  a  repeat  on  this  message.  Write  the 
procedure  signals  sent  by  DKT  in  calling  for  a  repeat. 

Answer.  VE    WZ1    V    DKT    II    NrS    IMI    AR. 

EATINGS. 


Each  question  counts  for  four  points. 
Technical : 

40  to  T6  points,  third  class. 
80  to  108  points,  second  class. 
112  to  124  points,  first  class. 
Procedure : 

8  to  12  points,  third  class. 
16  to  20  points,  second  class. 
24  to  32  points,  first  class. 

o 


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1940 


NOV  17 1940  to 


SEP  141942 


SIP  2  7 1983 

SANTA  BARBARA 


in  Interiibrary  Loan 
OCT  19 1983 


LD  21-50m-8,-32 


YC  62882 


UNIVERSITY  OF  CAUFORNIA  LIBRARY 


